a. Field of the Invention
The invention relates to apparatus for recording data regarding the operation of a sea borne vessel. More particularly, the invention relates to apparatus for recording and protecting data leading up to an accident or “incident”.
b. Brief Description of the Prior Art
It has long been noted that the investigation of maritime accidents and incidents could benefit from the recording of data and audible commands occurring aboard ships. Indeed, many considered this an inevitable technological extension of the time-honored ship's logbook. This desire has culminated in the development of an international standard governing the performance of a Voyage Data Recorder (VDR).
In 1974 the Safety of Life at Sea (SOLAS) Convention of the International Maritime Organization (IMO) acknowledged the value and expressed the desire of having recorders on ships similar to the “black box” flight recorders for aircraft. This began a long process of establishing international standards and requirements for a Voyage Data Recorder (VDR).
In 1996, VDR requirements, which had been debated for a long time, began to emerge in the navigation and electronics subgroup (NAV) of the IMO. Anticipating an eventual IMO resolution concerning VDRs, IEC (International Electrotechnical Commission) TC80 formed WG11, which began structuring a specification based on preliminary drafts of the NAV requirements. The IMO passed resolution A.861 (20) in November 1997 and the IEC standard 61996 was completed as a Committee Draft for Voting in March 1999. The specification was published in August 2000.
The IEC 61996 Ship borne Voyage Data Recorder Performance Requirements describes data acquisition and storage functions and refers to a “protective capsule” and a “final storage medium”. Architecture for complying with this standard has emerged with two major components.
In the first component, the ship's interfaces, data acquisition, and soft recording functions are encompassed in a Data Management Unit (DMU). The DMU is intended for installation in the relatively benign environment of the bridge. The second component is the Hardened Voyage Recorder (HVR) which encompasses the protective capsule and final storage medium. The HVR is designed for survivability and recoverability. It is intended for external installation on the bridge deck or on top of the superstructure.
The primary function of the Hardened Voyage Recorder (HVR) is to protect the data acquired by the Voyage Data Recorder (VDR) so that the data can be used during accident or “incident” investigation.